What is the root node of a tree?

• A node with no parent

• A node with two children

• A node with no children

• A node at the lowest level

Which of the following is true about trees?

• Trees can have cycles

• Trees can have multiple roots

• Trees are a type of graph

• Trees cannot be represented using linked lists

What is the degree of a node?

• Number of ancestors

• Number of children

• Number of siblings

• Number of edges

Which term refers to nodes with the same parent?

• Root

• Siblings

• Leaf

• Height

What is the height of a tree?

• The number of edges from the root to a node

• The total number of nodes in the tree

• The longest path from the root to a leaf

• The number of leaf nodes

Which of the following is true for a binary tree?

• Each node can have at most two children

• Each node can have an unlimited number of children

• A binary tree can have cycles

• The root node always has exactly two children

Which traversal visits the left subtree, then the root, then the right subtree?

• Preorder

• Inorder

• Postorder

• Level-order

Which tree traversal is useful for evaluating mathematical expressions?

• Preorder

• Inorder

• Postorder

• Level-order

Which data structure is used for level-order traversal of a binary tree?

• Stack

• Queue

• Linked List

• Heap

What is the time complexity of searching in a balanced binary search tree (BST)?

• O(1)

• O(n)

• O(log n)

• O(n²)